1. Introduction
NASA's Science Mission Directorate (SMD) has made a long-term commitment to building an inclusive open science community and has created a new open-source science initiative (OSSI) to help build a culture around openness [1]. To support this commitment to open-source science, and to implement NASA'S Strategy for Data Management and Computing for Groundbreaking Science [2], the SMD is building a OSSI infrastructure containing several key components. One such component is the SMD data catalog, whose goal is to support consistent discovery and access to complex scientific data across the SMD [2]. The SMD catalog project will enable integrated search and discovery of open data from the five SMD divisions, including Astrophysics, Biological and Physical Sciences, Earth Science, Heliophysics and Planetary Science. It should be noted that while the project is called ‘SMD Catalog’ it does not mean a single metadata catalog implementation but instead strives to implement an integrated search and discovery capability across the NASA SMD enterprise.